Pivot joints used in the linkages of work vehicles such as, for example, loader backhoes and four wheel drive loaders include pins and bushings to allow relative rotation between connected parts. These pivot joints conventionally include seals between the pins and the bushings as barriers to debris. However, due to the harsh environments in which these vehicles are used, i.e., environments having significant amounts of dirt and debris, dirt and debris tend to get past these barriers and cause accelerated wear of the pivot joints.
Some manufacturers of work vehicles have sought to remedy the difficulties outlined above by forming pre-barriers, i.e., a first line of defense against debris, via o-rings located between outer surfaces of the connected portions of linkages and work tools as shown in FIGS. 6 and 6A. However, this approach has led to at least the following two difficulties: (1) the o-rings are typically round, allowing dirt and debris to eventually work past the o-ring and into the space between the pins and bushings; and (2) the o-rings wear and their eventual replacement requires disconnection of the rotationally connected parts, a substantial expense with respect to time and money.